CAPE CANAVERAL, Fla. — The first American in space, Mercury astronaut Alan Shepard, was honored with his own stamp Wednesday on the eve of the 50th anniversary of his flight.

The Postal Service dedicated the Forever stamp Wednesday to commemorate Shepard's suborbital flight on May 5, 1961. He is the first astronaut to be honored, all by himself, on a stamp.

Twenty Shepard family members, including the late astronaut's three daughters, gathered at Kennedy Space Center with more than 100 others for the afternoon ceremony, held in an outdoor rocket garden. A replica of the black and white Mercury Redstone rocket that propelled Shepard on his 15-minute journey rose behind the stage.

One of the two surviving Mercury seven astronauts — Scott Carpenter — drew applause when he said he was pleased that a Forever stamp was chosen to honor Shepard. Forever stamps don't have a value on them and remain valid for first-class postage regardless of rate increases.

"That's appropriate to the stamp, but it is also appropriate to the time we should honor and remember Alan B. Shepard and Freedom 7," said Carpenter, wearing a navy ball cap adorned with the Mercury 7 emblem.

Carpenter laughed as he recalled that Shepard didn't like it that Soviet cosmonaut Yuri Gagarin beat him into space by less than a month. But he said the success of Shepard's flight helped lead America to the moon.

From Mercury to the moon
Shepard's Freedom 7 capsule soared 116 miles (185 kilometers) high and 302 miles (483 kilometers) to the east of Cape Canaveral. It reached a speed of 5,100 mph (8,160 kilometers per hour) before splashing down into the Atlantic.

Barely three weeks later, President John F. Kennedy committed the nation to landing a man on the moon by decade's end and bringing him back safely.

Shepard went on to command Apollo 14 in 1971 and became the fifth man to walk on the moon. He died in 1998 at age 74.

On Wednesday, Carpenter made note of "the first steps from the home planet that were taken by the family of man." Indeed, Shepard himself called his Mercury flight "just the first baby step, aiming for bigger and better things."

Daughter Julie Shepard Jenkins recalled how her father met with Kennedy at the White House a few days after the flight. While the two were talking, Caroline Kennedy skipped in.

"So John F. Kennedy introduced Caroline to the first American into space," Jenkins said. "She looked at Daddy and then she looked at her father with a very quizzical look. And she says, 'Where's the chimpanzee?' "

Science editor Alan Boyle's blog: "Astronaut Abby" is at the controls of a social-media machine that is launching the 15-year-old from Minnesota to Kazakhstan this month for the liftoff of the International Space Station's next crew.

Ham the chimpanzee rode a Mercury Redstone rocket into space on Jan. 31, 1961. The Mercury astronauts long contended America could been in space first if there hadn't been so many test flights.

"Daddy never thought of himself as a hero. He was just doing his job," Jenkins said. "And one last thing, please take advantage of your new ability to send our father into space again. Put a stamp on a letter."

More stamps to come
NASA Administrator Charles Bolden Jr., a former shuttle astronaut, said Shepard set an example for all those who followed him into space. All told, 335 Americans have rocketed toward space. There have been 164 U.S. manned space missions to date, all from Cape Canaveral.

"I look forward to giving the Postal Service plenty more ideas for stamps to honor the space program," Bolden said.

Shepard family members, astronauts, NASA officials and hundreds of others will gather again Thursday morning at the actual site from which Shepard blasted off, to mark the exact moment of liftoff: 9:34 a.m.

And on Saturday morning, a dozen or so former astronauts will take part in a parade in Cocoa Beach, riding in Corvettes just as the Mercury astronauts did so long ago.

John Glenn, the first American to orbit the Earth on Feb. 20, 1962, had to bow out of the anniversary festivities because of a death in the family.

On Wednesday, the Postal Service also issued a Forever stamp to honor NASA's Messenger spacecraft, the first to orbit the planet Mercury. It was launched from Cape Canaveral in 2004 and entered orbit around Mercury last month.

Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Cover boys

Fifty years ago, America's astronauts were celebrities. The cover of Life magazine's issue for March 3, 1961, featured Mercury astronauts John Glenn, Gus Grissom and Alan Shepard.
(Ralph Morse / Time & Life Pictures/Getty Image)
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Dining before flying

Astronauts Alan Shepard and John Glenn share breakfast in their robes just before Shepard's Freedom 7 spaceflight on May 5, 1961. Glenn, the prime backup pilot for Shepard's suborbital flight, would later become the first American to go into orbit.
(NASA)
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All bodily systems go

Alan Shepard has his blood pressure and temperature checked prior to his Freedom 7 flight. The attending physician is Dr. William K. Douglas.
(NASA)
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Suiting up

Inside the suiting trailer, astronaut Alan Shepard is dressed in his pressure suit and seated in a reclining chair while a technician checks communications equipment in his helmet.
(NASA)
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Looking in

Alan Shepard looks into the Freedom 7 capsule just before he climbs in for launch on May 5, 1961. Shepard was sealed inside the capsule for four hours while Mission Control dealt with technical glitches and weather-related delays. During one of the holds, Shepard urged ground controllers to "fix your little problem and light this candle."
(NASA)
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Silver spaceman

Alan Shepard's spacesuit was a full-body pressure suit originally developed by the B.F. Goodrich Co. and the U.S. Navy for wear by high-altitude fighter pilots. The suit's aluminized nylon exterior provides the classic silver look.
(NASA)
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'The clock has started'

Moments after the Freedom 7 launch, astronaut Alan Shepard called back, "Roger, liftoff, and the clock has started." During the ascent, Shepard experienced an acceleration of 6.3 g's. In comparison, shuttle astronauts typically experience a peak of 3 g's during launch and re-entry.
(NASA)
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Beautiful view

Astronaut Alan Shepard was the first American to see Earth from an altitude ranging as high as 116 miles. "On the periscope, what a beautiful view," he radioed. "Cloud cover over Florida. Three to four tenths near the eastern coast. Obscured up to Hatteras."
(NASA)
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Splashdown

After a little more than 15 minutes of flight, Alan Shepard's Freedom 7 capsule splashed down in the Atlantic, about 300 miles east of the Cape Canaveral launch pad. A Marine helicopter came to Shepard's rescue.
(NASA)
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Visiting the White House

President John F. Kennedy congratulates Mercury astronaut Alan Shepard during a Rose Garden ceremony on May 8, 1961, at the White House. Vice President Lyndon Johnson, NASA Administrator James Webb and several NASA astronauts are in the background. Less than a month later, Kennedy addressed Congress on his plan to put an American on the moon by the end of the decade.
(NASA)
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Enjoying the parade

After the spaceflight, astronaut Alan Shepard and his wife Louise ride in celebratory motorcade with Vice President Lyndon Johnson seated between them in the back seat.
(Ralph Morse / Time & Life Pictures/Getty Images)
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The centerpiece of the Graduates in Space exhibit at the U.S. Naval Academy Visitors Center in Annapolis, Md. is the Freedom 7 space capsule, flown into space in 1961 by Naval Academy graduate Alan B. Shepard, Jr.(Class of 1945).
(U.S. Naval Academy)
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50 years later

Alan Shepard went on to walk on the moon as commander of the Apollo 14 mission in 1971, and passed away in 1998 at the age of 74. On May 4, 2011, a stamp set commemorating the 50th anniversary of Shepard's Mercury flight as well as the Messenger mission to Mercury was unveiled at Kennedy Space Center Visitor Complex in Florida. Among the special guests at the ceremony was Alan Shepard's daughter, Julie Shepard Jenkins.
(Michael R. Brown / AP)
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Editor's note:
This image contains graphic content that some viewers may find disturbing.